Most purifier claims ask you to trust a brochure. This one has a paper trail, so it is worth walking through what was actually measured — including the parts that are less flattering.
How the test was run
IAPMO India tested the Biofier across fifteen conditions: feed water at 250, 500, 750, 1,000 and 1,500 mg/L TDS, each at three hardness levels between 100 and 400 mg/L. A competitor RO was tested separately across four conditions.
That range is deliberate. It covers most of what comes out of an Indian tap, from soft municipal supply to hard borewell water.
The pH result
All fifteen conditions produced water between pH 6.75 and 7.21 — neutral, and inside the BIS range of 6.5–8.5. Feed water had been slightly acidic at 6.33–6.89, so it came out closer to neutral than it went in.
The competitor RO came out at pH 9.69–9.77 in all four of its conditions, above the BIS limit. It strips the water and then corrects it with an alkaline stage — and overshoots.
The result that matters most
Feed water was varied six-fold on dissolved solids and four-fold on hardness. The water coming out barely moved: TDS between 63 and 192 mg/L, hardness between 12 and 29.
That consistency is easy to overlook and hard to achieve. Indian water changes by city, by season and by source.
Contaminants
- Nitrate below 5 mg/L in every test, from feed carrying up to 20. The BIS limit is 45.
- Hardness under 29 mg/L even from feed at 428 — no scaling.
- Sulphate never above 13.6 mg/L against a BIS limit of 200.
- Rejection scales with contamination — 53% at 250 mg/L feed, rising to 93% at 1,500.
Water recovery
The Biofier recovered 54.6–72.7%. The competitor managed 47.4–52.3%. Over five years, for a household drinking eight litres a day, that is roughly 15,600 litres.
These reports measure contaminant reduction, pH, recovery and consistency. They are not a mineral-retention study, and we have deliberately not drawn mineral-retention claims from them. Where you see a mineral figure quoted elsewhere, ask what it was measured against.
Why publish all of it
Because selective quotation is what made this category hard to trust. The pH finding is strong, the consistency finding is the most useful, and the mineral question needs its own study rather than a convenient reading of this one.
